OP0054 REDUCING THE BURDEN OF LOW BACK PAIN: RESULTS FROM A NEW MICROSIMULATION MODEL
Authors: J. Kopec, E. C. Sayre, J. Cibere, L. Li, H. Wong, A. Okhmatovskaia, J. Esdaile
Journal: Annals of the Rheumatic Diseases (2022)

Background Low back pain (LBP) has been the leading cause of disability worldwide for the past 30 years. In 2019, LBP was responsible for 64 million years lived with disability (YLDs) [1]. Objectives The purpose of the present study was to project and compare the impact of three strategies for reducing the population health burden of LBP: weight loss, ergonomic interventions, and an exercise program. Methods We have developed a microsimulation model of LBP in Canada using a novel simulation platform, SimYouLate. The initial population was derived from Cycle 1 (2001) of the Canadian Community Health Survey (CCHS). We modeled an open population 20 years of age and older. Key variables included age, sex, education, body mass index (BMI), type of work, having a back problem, pain level in persons with back problems, and exercise. The effects of interventions on the risk of LBP were obtained from the CCHS for the effect of BMI, the Global Burden of Disease Study for occupational risks, and a published meta-analysis for the effect of exercise. All interventions lasted from 2021 to 2040. Strength of the interventions varied over a wide range. YLDs were defined as LBP prevalence multiplied by disability weight. The population health impact of the interventions was calculated as a difference in YLDs between the base-case scenario and each intervention scenario and expressed as YLDs averted per intervention unit and as % of total LBP-related YLDs. Results In the base-case scenario, LBP in 2020 was responsible for 424,900 YLDs in Canada and the amount increased to 460,312 YLDs in 2040. The effects of the interventions on YLDs were as follows: 27,993 (95% CI 23,373, 32,614) YLDs averted over 20 years per 0.1 unit change in log-transformed BMI (10.5% change in BMI) among overweight and obese individuals, 19,416 (16,275, 22,557) YLDs averted per 1% reduction in the proportion of workers exposed to occupational risks, and 26,058 (22,455, 29,661) YLDs averted per 1% increase in the proportion of eligible patients with back problems participating in the exercise program. Table 1 shows the intervention impact as % of total LBP-related YLDs and Figure 1 shows YLD-equivalence between the interventions. A one unit reduction in BMI per year among the overweight and obese individuals would be approximately equivalent in terms of disability reduction to an effective ergonomic intervention in 35% of at-risk workers and an exercise intervention in 27% of eligible patients with back problems over the same period (Figure 1). Table 1. YLDs averted between 2021 and 2040 as % of total LBP-related YLDs, according to intervention type and level, in persons aged 20+ in Canada Intervention Effect (%) 95% LCL 95% UCL Reduction in BMI per year 0.1 1.4 -1.4 4.1 0.3 4.8 2.2 7.3 0.5 6.3 3.9 8.8 1.0 8.5 6.0 11.0 3.0 11.9 9.4 14.4 5.0 13.5 10.9 16.0 Reduction in occupational exposure 20% 5.2 1.9 8.5 40% 9.5 6.4 12.7 60% 13.8 10.6 16.9 80% 18.1 14.8 21.4 100% 22.4 18.8 25.9 Increase in exercise participation 20% 6.6 2.8 10.4 40% 12.4 8.7 16.0 60% 18.1 14.5 21.7 80% 23.9 20.1 27.6 100% 29.6 25.5 33.7 LCL: lower confidence limit. UCL: upper confidence limit. Figure 1. Equivalence between BMI, ergonomic and exercise interventions in terms of their impact on YLDs. Each point represents a specific number of YLDs averted. Values on the y-axis show reduction in % of workers at risk and increase in % exercising that are required to achieve the same reduction in YLDs as the corresponding reduction in BMI shown on the x-axis. Conclusion This is the first population-based microsimulation study to compare currently available preventive strategies in LBP in terms of YLDs averted and to provide measures of equivalence between these strategies. References [1]Hartvigsen J, Hancock MJ, Kongsted A, et al. What low back pain is and why we need to pay attention. Lancet 2018;391(10137):2356-2367. Acknowledgements The study was supported by a grant from the Canadian Institutes for Health Research (FRN 142440). Disclosure of Interests None declared.